The invention relates to a centrifugal sorter comprising a motor driven feed plate inclined relative to a horizontal and driven by means of a drive device about an inclined rotation axis, the motor driven feed plate forming a base of a container for workpieces; and a ring rotatable about an approximately vertical axis by means of another drive devices wherein the ring surrounds the feed plate, is substantially horizontal and provides a delivery location for the workpieces fed outwardly and upwardly from the container under the influence of centrifugal force approximately in the vicinity of the highest peripheral section of the feed plate. The container wall is spherical sector shaped and the other drive device has a drive member driven by a motor which acts on the outer side of the ring to rotate it.
A centrifugal sorter of this type is known from European Patent Application EP 729 906 A2, in which the ring is enclosed under the plate with spacing and is supported vertically, axially and radially like a top by means of a suitable bearing mechanism. This top is connected with a drive mechanism for rotating it, which has a control gear driven by a motor, which meshes with a ring gear which is mounted on the underside of a circular flange. The circular flange is arranged around the upper outer edge of a ring or guide member and is formed approximately like a truncated cone which tapers in an upward direction. Thus the drive device associated with the ring is located in the upper outer region of the ring. The feed plate arranged inside the ring is inclined and has a drive device which is located under the feed plate and thus above the base or bottom of the container. The container bottom is thus a fixed mounting member for the drive device associated with the feedplate.
This known centrifugal sorter is not suitable for a steam sterilization in an autoclave in regard to its parts which come into contact with the workpiece. The container together with the circular flange and ring gear connected with it cannot be disassembled so that it may be fed to an autoclave for steam sterilization and then again reassembled. This is also true for the feed plate inside the container which is not detachable from its drive mechanism located under it. The known centrifugal sorter also allows no sterilization and no isolation technique in an assembled operating state, in which a bell is inverted over the centrifugal sorter, which is sealed tightly to the centrifugal sorter and surrounds an interior protected zone and remains there permanently during operation. A sterilization in an assembled operating state of the centrifugal sorter can be performed by means of this bell usually at the beginning of the operating cycle. In this sterilization air inside the bell is dried and then e.g. the water content is replaced by a suitable sterilization medium, e.g. H.sub.2 O.sub.2 (hydrogen peroxide), which has a sterilizing effect. The parts of the centrifugal sorter inside the bell are sterilized by evacuating and again feeding the sterilizing medium into the bell. After that the sterilizing medium is rinsed out of the bell and then replaced by a laminar flow of fresh air which is maintained through the bell. An aggressive atmosphere is maintained in the above-described so-called isolator technique, to which the selected or particular individual materials are not exposed to as in the known centrifugal sorter. In the known centrifugal sorter the drive mechanism of the ring with all components and also the drive mechanism for the feed plates with all components are completely exposed to this aggressive atmosphere which thereby causes damaged to occur.
The other centrifugal sorters have approximately the same disadvantages.